Proficiencies in Appraisals

I’m trying to set the proficiencies of a quantity scale in Appraisals as follows:

0-1,49 (scale interval 0,01, unit of measurement X)

1,5-2,49 (scale interval 0,01, unit of measurement Y)

2,5-3,49 (scale interval 0,01, unit of measurement Z)

3,50-4 (scale interval 0,01, unit of measurement L)

And I get the message ‘Target key must be different from source key’ (mess #SV015). Could you please let us know on how to resolve this?